Javascript AngularJS:注入$timeout在指令中不可用

我正在向以下指令中注入

$timeout

，但它没有定义

以下代码将未定义的打印到控制台并抛出TypeError:$timeout不是一个函数

---

我认为问题在于，你没有注入任何东西，你只是指定了一个参数

$timeout

，它就像一个可能被注入的服务的占位符。要修复此问题，请添加

foo.$inject=['$timeout']到文件末尾，如下所示：

export default class foo {
    constructor ($timeout) {
        'ngInject';
        this.restrict = 'A';
        this.scope = {};
        this.$timeout = $timeout;

        console.log( $timeout );
        $timeout( function() {
            alert('timeout');
        }, 0 );
    }

    link($scope, $element, $attrs, $ctrl) {      

    }

    // Create an instance so that we can access this inside link
    static factory() {
        foo.instance = new foo();
        return foo.instance;
    }
}

foo.$inject = ['$timeout'];

有几个例子也分别从类定义中进行注入

或者要通过静态工厂（正如您可能打算的那样），文件末尾将是
foo.factory.$inject=['$timeout']
，并且您还必须调整工厂函数，以便为您提供并传递注入的服务：

export default class foo {
    constructor ($timeout) {
        'ngInject';
        this.restrict = 'A';
        this.scope = {};
        this.$timeout = $timeout;

        console.log( $timeout );
        $timeout( function() {
            alert('timeout');
        }, 0 );
    }

    link($scope, $element, $attrs, $ctrl ) {      

    }

    // Create an instance so that we can access this inside link
    static factory($timeout) {
        foo.instance = new foo($timeout);
        return foo.instance;
    }
}

foo.factory.$inject = ['$timeout'];

export default class foo {
    constructor ($timeout) {
        'ngInject';
        this.restrict = 'A';
        this.scope = {};
        this.$timeout = $timeout;

        console.log( $timeout );
        $timeout( function() {
            alert('timeout');
        }, 0 );
    }

    link($scope, $element, $attrs, $ctrl ) {      

    }

    // Create an instance so that we can access this inside link
    static factory($timeout) {
        foo.instance = new foo($timeout);
        return foo.instance;
    }
}

foo.factory.$inject = ['$timeout'];